Brake pads are generally fixed on pins and inserted in specific seats included in the brake caliper body. Said seats are shaped so as to leave mechanical play between seat walls and pad so as to facilitate the operations of assembling and disassembling the brake pad.
However, including said although minimum mechanical play, particularly along a direction tangential to the braking surface of an associable brake disc, or tangential direction, allows the brake pad pressed against the braking surface of the disc to move and accelerate in order to follow the tangential direction. Annoying noise phenomena, such as for example the well-known knocking noise, occur during the braking action, when the pad stops against tangential abutments of its seat.
This problem is amplified while the vehicle is traveling, particularly in the case of high-performance vehicles, when dust and dirt accumulate in the gaps left between pads and pad-housing seat walls. These dust and dirt become compacted, tending to block the brake pad in position during the braking action, which pad requires more tangential force to slide on the braking surface thus resulting in an even louder knocking noise. For example, these known drawbacks occur when, after a given distance on which the vehicle is traveling forwards, it proceeds in reverse and then brakes.
Some known solutions of noise-prevention devices have been suggested with the purpose of providing a brake caliper adapted to provide the quietest braking action possible. For example, document U.S. Pat. No. 4,699,254 shows a blade spring which is mounted between an upper portion of the brake pad and an upper opening of the caliper body, said blade spring is adapted to exert a tangential braking action on a portion of the brake pad. This solution, although partially advantageous, is very cumbersome and rather laborious to mount, because the spring extends towards a dedicated opening provided in the upper portion of the caliper body.
For example, document U.S. Pat. No. 564,961 shows a blade spring adapted to grip, with a “C”-shaped portion thereof, a side extension of the pad, in order to damp the displacements of the brake pad during the braking action. This solution forces side protections on the brake pad, like ears, to achieve the coupling with the spring. Therefore, the pad-housing pocket provided in the caliper body must contain recesses adapted to house said side protections, or ears, of the brake pad.
For example, international patent WO-2005-064193 to the same Applicant shows a type of blade spring adapted to be mounted on the brake caliper body and connected to a side portion of the pad. This solution, although partially advantageous, does not fully solve the problem, because it obliges in all cases to include lock pins fixed in eyelets of the pad so as to limit the tangential displacement of the pad itself during the braking action. Furthermore, the spring shown in this document is difficult to be assembled, disassembled and maintained because it is mounted about a protuberance made in the caliper body. A further example is shown in document WO-2005-064191.
The need is thus felt to provide a spring and a brake pad, as well as a brake caliper, capable of avoiding, or at least limiting, the onset of annoying noisy phenomena during the braking action, without requiring inconvenient and difficult assembly, disassembly and maintenance procedures.
Similarly, the need is felt to provide a brake pad capable of damping the accelerations between brake pad and caliper body which arise during the braking action.